DZone Snippets: Jlong's Code Snippets

Object#subclasses

jlong (John W. Long) — Mon, 13 Nov 2006 20:13:04 GMT

Find every subclass of an object. Limit the query to direct descendants by setting direct to true.



require 'test/unit'



class Object

  def self.subclasses(direct = false)

    classes = []

    if direct

      ObjectSpace.each_object(Class) do |c|

        next unless c.superclass == self

        classes << c

      end

    else

      ObjectSpace.each_object(Class) do |c|

        next unless c.ancestors.include?(self) and (c != self)

        classes << c

      end

    end

    classes

  end

end



class TrackSubclassesTest < Test::Unit::TestCase



  class A; end

  class B < A; end

  class C < B; end

  class D < A; end

  class E; end

  class F < E; end

  

  def test_subclasses

    assert_equal [F], E.subclasses

    assert_equal [C], B.subclasses

    assert_equal [B, D], A.subclasses(true).sort_by { |c| c.name }

    assert_equal [B, C, D], A.subclasses.sort_by { |c| c.name }

  end

  

end

Rails and Vim

jlong (John W. Long) — Sat, 29 Jul 2006 03:00:20 GMT

A simple command for opening related Rails project files in Vim:



#!/usr/bin/env ruby



if ARGV.empty?

  puts "usage: #{File.basename($0)} string" 

  puts "  Scans related Rails directories for " + 

         "files begining with string " 

  puts "  and opens them in vi." 

  exit

end



files = []

ignore = [/CVS$/]



# Find models or controllers that match args

ARGV.each do |arg|

  models = Dir["app/models/#{arg}*"]

  controllers = Dir["app/controllers/#{arg}*"]

  files += models + controllers

end



# Remove duplicates

files.sort!.uniq!



# Add unit tests for models

files.grep(%r{app/models/(.*?).rb}) do

  tests = Dir["test/unit/#{$1}_test.rb"]

  files += tests

end



# Add views and functional tests for controllers

files.grep(%r{app/controllers/(.*?)_controller.rb}) do

  views = Dir["app/views/#{$1}/*"]

  tests = Dir["test/functional/#{$1}_controller_test.rb"]

  files += views + tests

end



# Add views and fixtures for mailers

files.grep(%r{app/models/(.*?_mailer).rb}) do

  views = Dir["app/views/#{$1}/*"]

  fixtures = Dir["test/fixtures/#{$1}/*"]

  files += views + fixtures

end



# Again remove duplicates

files.sort!.uniq!



# Remove files that match ignore list

files.delete_if do |filename|

  result = false

  ignore.each do |i|

    if filename =~ i

      result = true

      break

    end

  end

  result

end



system "vi -o #{files.join(' ')}"

Drop it in a file called "edit" in your path and you can open related rails files with a few key strokes:



# open AccountController and related tests and views:

edit account_c



# open AccountMailer and related tests, views, and fixtures:

edit account_m



# open everything related to accounts:

edit account

A detailed explanation here: http://wiseheartdesign.com/articles/2006/07/27/rails-and-vim/.

Testing Rails Validations

jlong (John W. Long) — Tue, 17 Jan 2006 20:25:14 GMT



#

# Useful for testing Rails ActiveRecord validations. For more information see:

# http://wiseheartdesign.com/articles/2006/01/16/testing-rails-validations/

#

module ValidationTestHelper

  def assert_valid(field, message, *values)

    __model_check__

    values.each do |value|

      o = __setup_model__(field, value)

      if o.valid?

        assert_block { true }

      else

        messages = [o.errors[field]].flatten

        assert_block("unexpected invalid field <#{o.class}##{field}>, value: <#{value.inspect}>, errors: <#{o.errors[field].inspect}>.") { false }

      end

    end

  end

  

  def assert_invalid(field, message, *values)

    __model_check__

    values.each do |value|

      o = __setup_model__(field, value)

      if o.valid?

        assert_block("field <#{o.class}##{field}> should be invalid for value <#{value.inspect}> with message <#{message.inspect}>") { false }

      else

        messages = [o.errors[field]].flatten

        assert_block("field <#{o.class}##{field}> with value <#{value.inspect}> expected validation error <#{message.inspect}>, but got errors <#{messages.inspect}>") { messages.include?(message) }

      end

    end

  end

  

  def __model_check__

    raise "@model must be assigned in order to use validation assertions" if @model.nil?

    

    o = @model.dup

    raise "@model must be valid before calling a validation assertion, instead @model contained the following errors #{o.errors.instance_variable_get('@errors').inspect}" unless o.valid?

  end

  

  def __setup_model__(field, value)

    o = @model.dup

    attributes = o.instance_variable_get('@attributes')

    o.instance_variable_set('@attributes', attributes.dup)

    o.send("#{field}=", value)

    o

  end

end